Router path duplication with --base in Slidev v52

[mrsimpson]

Bug Description

When using --base /path/ with Slidev v52.16.0, navigating to the next slide causes the URL to incorrectly duplicate the base path: /path/path/2 instead of /path/2.

Minimal Reproduction

git clone https://gist.github.com/mrsimpson/d44bb8c60d9540450f99d88a166eab17.git
cd slidev-bug-repro
npm install
npm run build -- --base /test-slides/
npx vite preview --base /test-slides/

Open http://localhost:4173/test-slides/1 and click 'next slide'.

Expected: http://localhost:4173/test-slides/2
Actual: http://localhost:4173/test-slides/test-slides/2

Environment

• Slidev version: 52.16.0
• Node.js: 20/24
• OS: macOS/Windows/Linux

Notes

• This bug only occurs with npm run build + vite preview, not with npm run dev
• Works correctly in Slidev 0.50.x
• Affects GitLab Pages deployments with subdirectory paths

[inaku-Gyan]

I met the same issue, and tried to fix it in #2630.

[ifigueroap]

Just upgraded to 0.52 and got hit by this bug too. Claude is making a patch-package fix as we speak:

diff --git a/node_modules/@slidev/client/logic/slides.ts b/node_modules/@slidev/client/logic/slides.ts
index cb156a1..482111a 100644
--- a/node_modules/@slidev/client/logic/slides.ts
+++ b/node_modules/@slidev/client/logic/slides.ts
@@ -21,7 +21,7 @@ export function getSlidePath(
     route = getSlide(route)!
   const no = route.meta.slide?.frontmatter.routeAlias ?? route.no
   const path = exporting ? `export/${no}` : presenter ? `presenter/${no}` : `${no}`
-  return `${import.meta.env.BASE_URL}${path}`
+  return `/${path}`
 }
 
 export function useIsSlideActive() {

[barabasss]

Confirmed on a real GitHub Pages project-site deploy (--base /<repo>/, history routing, Slidev 52.16.0). Paging to the next slide produces /<base>/<base>/2 and Slidev's NotFound; direct deep-links work, and dev works (base /).

Same root cause as #2630 — getSlidePath() returns ${import.meta.env.BASE_URL}${path} while the router is already created with createWebHistory(import.meta.env.BASE_URL), so the base is applied twice during navigation. The same base-prefixing also breaks openSlideInNewTab() in the overview (pathPrefix + path.slice(1) → doubled).

Reverting getSlidePath to a base-relative path (as in #2630) fixes both — verified end-to-end with a headless build + --base (paging, deep links, refresh all OK). 🙏 for getting #2630 merged.

[zhangyx1998]

Just ran into the same problem, wondering if there exist a workaround without patching into the package.

[inaku-Gyan]

Just ran into the same problem, wondering if there exist a workaround without patching into the package.

You can downgrade Slidev to v52.15.2, just the previous version.